Everytime I try to download something off limewire it goes immediately to 100% and the status says Disk Problem. How can I fix this?

I have:

• an administrator account on windows vista
• a norton 360 running with the firewall (but I've been able to download things through this before)
• 2 GB RAM
• 61.7 GB free space
• Broadband (and this happens on my dad's and my wireless connection)
• I haven't changed anything in my system lately